For a mobile communication system, user equipment (UE) in the Cell_Paging Channel (Cell_PCH) state cannot receive and send data directly before the feature of receiving data from High Speed Downlink Packet Access (HSDPA) channel by the UE in Cell_PCH state channel is introduced. For example, when the UE in the Cell_PCH state wants to transmit uplink data, the UE must initiate a CELL UPDATE procedure in order to enter into other states. The UE can transmit the uplink data only after the UE completes the CELL UPDATE procedure and enters a state in which the UE is allowed to transmit uplink data directly.
In the prior art, a UE in the Cell_Forward Access Channel (Cell_FACH) state can transmit the uplink data directly. After the feature of receiving data from HSDPA channel by the UE in the Cell_PCH state being introduced, the UE in the Cell_PCH state can reserve the resources of the UE in the Cell_FACH state. When the UE has uplink data to transmit, the UE can perform state transition from the Cell_PCH state to the Cell_FACH state directly, so that the UE can send and receive data by using the reserved resources in the Cell_FACH state, without initiating a CELL UPDATE procedure.
The prior art has the following disadvantages:
When the UE in the Cell_PCH state wants to transmit a large volume of uplink traffic, the resources reserved by the UE in the CELL_FACH state may not satisfy the quality of the service. In this case, only after the radio resource control (RRC) state machine of the UE is set to the Cell_FACH state, the UE could indicate the network side to configure resources that are more suitable to meet the quality of the service for the UE. Then the network side can determine to configure suitable resources for the UE to transmit the uplink data accordingly. Obviously, this solution for triggering the resource configuration may cause a delay for the UE in subsequent data transmission.